1. Field of the Invention
The present invention relates to a backlight unit capable of easily forming a curved or three-dimensional shape, and more particularly, to a backlight unit, in which a heat radiating plate comprises a thin plate so that a light guide panel has a curved shape, thus easily conforming to a PCB (Printed Circuit Board) even when it is installed to have a curved shape, and which has excellent waterproofness, to protect a luminous means and a circuit even when the backlight unit is installed under water, thus maximizing the lifespan of a lamp.
Further, the present invention relates to a backlight unit capable of easily forming a curved or three-dimensional shape, which is constructed so that the front of a light guide panel is neat and tidy, and all components including an electric wire are accommodated within the thickness of the light guide panel, thus being resistant to external interference or impact, being easy to handle, and minimizing the likelihood of damage thereto. Further, the present invention facilitates packaging or installing operation, and enables the manufacturing of various shapes of backlight units, using a flexible PCB.
2. Description of the Related Art
Generally, a backlight unit used for an LCD (Liquid Crystal Display), advertisement, illumination, floor illumination, a decoration, etc. includes a light guide panel comprising a light transmittable acrylic plate or a transmittable plate made of a mixture of acryl and a light diffusing substance. A lamp, which emits light, is mounted on one side of the light guide panel. A predetermined pattern of notches, an uneven dot pattern, a printed dot pattern, or a sanded surface is provided on a surface of the light guide panel so as to guide the optical path or light diffusion of the lamp.
FIG. 1a is a rear view showing the construction of a conventional backlight unit 100, and FIG. 1b is a detailed sectional view taken along line A-A of FIG. 1a. 
Referring to FIGS. 1a and 1b, the backlight unit is constructed as follows. That is, lamps 131 emitting light are provided on one side of a light guide panel 110 which is made of a light transmitting material. A plurality of V-shaped notches 112 is formed on the back surface of the light guide panel 110 in horizontal and vertical directions so as to uniformly diffuse light emitted from the side of the light guide panel 110 toward the front of the light guide panel 110 to which a display film 140 is attached. A reflection sheet 150 made of a PET material may be adhered to the back surface of the light guide panel 110 having the V-shaped notches.
Further, a heat radiating plate 180 is secured to a PCB 133 having the lamps 131, and a bracket 170 is additionally installed to support the lamps 131, the heat radiating plate 180, etc.